The present inventions relate generally to tomography systems and, more particularly, to a table for supporting a sample, such as a patient, in a tomography scanner during a scanning procedure. Even more particularly, the present inventions relate to a lifting apparatus and method for a patient table.
Medical diagnostic imaging and scanner systems such as magnetic resonance imaging (MRI) apparatus, X-ray machines, positron emission tomography (PET) scanners, and computer tomography (CT) scanners are well known. Such machines are quite popular as a tool for providing images of internal portions of patients for diagnosis of medical conditions, such as internal injuries, cancerous tumors and the like. Owing to good quality tomographic images with low dosage X-ray radiation, the CT scanner has become especially well accepted by the medical profession for examining patients and diagnosing medical conditions.
An annular gantry normally supports many of the components of a CT scanner and includes an outer ring secured to a stand and an inner ring mounted for rotation within the outer ring. During a scanning procedure, a pallet of a patient table is extended through the center of the gantry and the inner ring is rotated about the pallet. A patient lies on the pallet within the center of the gantry during the scanning procedure. The components supported by the gantry can include an x-ray tube for providing the x-ray beam, one or more high voltage power supplies, balancing weights, a data acquisition module, and a bank of detectors diametrically opposed from the x-ray source. At least some of these components are secured in the inner ring for rotation therewith.
In order to obtain tomographic images of a patient with a CT scanner or X-ray CT apparatus, it is necessary that the patient be located exactly at a predetermined position inside the opening of an annular scan gantry of the apparatus. For this reason, such apparatus has been provided with a patient handling couch or table which is moveable vertically to be in line with an axis of rotation of the scan gantry, and moveable horizontally, or axially in and out of the scan gantry parallel with the axis of rotation.
Several patient tables are known for this purpose. For example, U.S. Pat. No. 4,576,368 to Ogawa, et al. shows a table mechanism suitable for use in a tomographic system, such as an x-ray computer tomography system. The table mechanism has a table movable upwardly and downwardly by a parallel link mechanism. The distance of horizontal movement of a cradle on the table can be automatically compensated for, dependent on an angle of angular movement of the parallel link mechanism, while holding the cradle and a gantry, relatively positioned in a constant relation. A side of the parallel link mechanism is covered with a cover mechanism having a relatively small area.
U.S. Pat. No. 5,657,498 to Hum shows an apparatus and method for determining a cradle support elevation in an imaging system. In one form, the apparatus includes a support rail secured to and between table support legs of a table arrangement. The support rail is maintained substantially parallel with the cradle support. An encoder, coupled to the support rail, generates signals indicative of the cradle support elevation. The encoder signals can be used to determine, using a linear function, cradle support elevation. More specifically, although the cradle support movements are non-linear, the cradle support elevation apparatus provide linear feedback which may be used to determine cradle support elevation.
Other U.S. patents also showing various patient tables include: U.S. Pat. Nos. 4,131,802; 4,567,894; 4,568,071; 4,613,122; 4,727,328; 4,914,682; 4,984,774; 5,058,871; 5,066,915; 5,199,123; 5,204,629; 5,273,043; and 5,960,054. Many of these patents show patient tables having xe2x80x9cscissors-typexe2x80x9d lifting assemblies.
What is still desired, however, is a new and improved patient support couch or table apparatus for use with medical diagnostic imaging and scanner systems. In particular, what is desired a patient table having an improved lifting apparatus.
Among other features and advantages, the lifting apparatus will preferably provide a combination of both vertical and horizontal movement of the patient table. The lifting apparatus will also preferably nest in its lowered position in order to minimize the table""s overall height when lowered.
The lifting apparatus will preferably also be provided with a new and improved cover assembly for covering and protecting the apparatus throughout the apparatus"" full range of motion, a new and improve manual jack assembly for allowing manual operation the lifting apparatus upon a loss of power, and a new and improved sensor assembly for providing an indication of the vertical and horizontal position of the table during operation of the lifting apparatus.
The present inventions provide a new and improved patient table. A patient table constructed in accordance with the present inventions can be used for, but is not limited to, positioning a patient within an imaging gantry of a tomography scanner system.
According to one exemplary embodiment of the present inventions, the patient table includes a new and improved lifting apparatus that provides a combination of both vertical and horizontal movement of the patient table. The new and improved lifting apparatus also nests in its lowered position in order to minimize the table""s overall height when lowered.
The lifting apparatus includes a lower base, an upper base securable to the table assembly, and at least one pair of non-intersecting front and rear lift arms holding the upper base vertically above the lower base. Each lift arm includes a lower end pivotally connected to the lower base, an upper end pivotally connected to the upper base, an elbow located between the lower end and the upper end, an elongated lower portion extending between the lower end and the elbow, and an elongated upper portion extending from the elbow to the upper end, with the lower portion and the upper portion connecting at an angle at the elbow.
According to another exemplary embodiment of the present inventions, the patient table includes a new and improved cover assembly for covering and protecting the lifting apparatus throughout the apparatus"" full range of motion.
According to an additional exemplary embodiment of the present inventions, the patient table includes a new and improved manual jack assembly for allowing manual operation the lifting apparatus upon a loss of power.
According to a further exemplary embodiment of the present inventions, the patient table includes a new and improved sensor assembly for providing an indication of the vertical and horizontal position of the table during operation of the lifting apparatus.
The foregoing and other features and advantages of the present inventions will become more readily apparent from the following detailed description of the disclosure, as illustrated in the accompanying drawing.